This invention relates to positioning means for rail vehicles, said means being of the kind in which a positioning carriage is movable along a path parallel to the rail track on which a train of rail vehicles runs, a positioner arm on the carriage being displaceable to and from a transversely projecting position in which it is located between a pair of vehicles of the train and connects the carriage thereto for moving the train to a required position along the track. Such means are employed, for example, in tippling installations for the discharge of bulk materials.
One known form of positioning means of this kind is described in UK Patent Specification No. 1,119,965 where a positioning carriage is provided with an arm that can be swung downwards from a retracted upright position to a horizontal extended position in which it is located adjacent the central coupling means between a pair of railroad cars. By having the driving connection from the positioning carriage disposed near the central vertical plane of the vehicles, the movement and control of heavy train loads is facilitated but there are disadvantages in this known arrangement, particularly as regards of controlling the movement of the arm as this is necessarily relatively massive.
In addition, there can sometimes be problems in providing access between vehicles for the movement of the arm to and from its operative position because in many designs of railroad car ancillary equipment and fittings overhang the ends of the vehicle.